The present invention relates to an electrical gas-discharge lamp comprising an inner bulb arranged within an outer bulb, said inner bulb being filled with a discharge gas and comprising a first electrode and an opposing second electrode having a distance from the first electrode which allows ignition of a gas-discharge in said inner bulb by applying an ignition voltage between the electrodes.
Such a construction allows the realization of high-intensity discharge (HID) lamps for automotive applications, in which the inner bulb is filled with the discharge gas at high pressure. This high pressure allows a high intensity of the light emitted by the lamp with only a small delay after ignition which is necessary in the automotive field. Due to the high pressure of the discharge gas in the inner bulb automotive HID lamps require notoriously high ignition voltages of the order of 20 kV in order to ensure sufficient luminous flux already after a few seconds of operation. This particularly applies to automotive HID lamps. The high ignition voltage however requires a complex, expensive ignition circuit.